Semiconductor apparatus and potential measuring apparatus

Abstract

The present disclosure relates to a semiconductor apparatus and a potential measuring apparatus capable of preventing electrostatic breakdown in an electrode formation process when an electrode and an amplifier are provided on a same substrate. A diode is provided of which a cathode is connected to a previous stage of an amplifying transistor for amplifying a signal read by a read electrode for reading a potential having contact with liquid in which a specimen is input and an anode is grounded. With such a configuration, by bypassing a negative charge generated between the electrode and the amplifying transistor in the electrode formation process from the diode and discharging the negative charge toward ground so as to prevent electrostatic breakdown. This is applicable to a bioelectric potential measuring apparatus.

The invention claimed is: 
     
       1. A semiconductor apparatus comprising:
 a reference potential generating unit and a reference potential electrode configured to supply a reference potential to liquid; 
 a read electrode and an amplifier configured to read a signal from the liquid; and 
 a protection portion configured to protect the amplifier from a negative charge at a previous stage of the amplifier, wherein 
 the reference potential generating unit, the reference potential electrode, the read electrode, the amplifier, and the protection portion are installed on a same substrate. 
 
     
     
       2. The semiconductor apparatus according to  claim 1 , wherein
 the protection portion bypasses the generated negative charges to the amplifier via a wiring connected to the read electrode and the reference potential electrode at a time of an electrode formation process for forming the read electrode and the reference potential electrode to protect the amplifier. 
 
     
     
       3. The semiconductor apparatus according to  claim 2 , wherein
 the amplifier is an amplifying transistor, 
 the read electrode is connected to a gate of the amplifying transistor, and 
 the protection portion is a protection diode of which a cathode is connected to a previous stage of the gate on the wiring for connecting the read electrode and the amplifying transistor, and an anode is grounded. 
 
     
     
       4. The semiconductor apparatus according to  claim 3 , further comprising:
 an additional protection portion, of which an anode is connected to the cathode of the protection diode, a cathode is connected to a predetermined power source, having IV (current voltage) characteristics same as the protection diode. 
 
     
     
       5. The semiconductor apparatus according to  claim 4 , wherein
 a voltage of the predetermined power source is higher than the reference potential. 
 
     
     
       6. The semiconductor apparatus according to  claim 5 , wherein
 the predetermined power source is a power source of the amplifying transistor. 
 
     
     
       7. The semiconductor apparatus according to  claim 3 , further comprising:
 another protection portion configured to protect the amplifier from a negative charge at a previous stage of the reference potential generating unit. 
 
     
     
       8. The semiconductor apparatus according to  claim 7 , wherein
 the another protection portion bypasses the generated negative charge to the reference potential generating unit via wiring connected to the reference potential electrode and the reference potential generating unit at a time of an electrode formation process for forming the read electrode and the reference potential electrode to protect the reference potential generating unit. 
 
     
     
       9. The semiconductor apparatus according to  claim 8 , wherein
 the another protection portion is another protection diode of which a cathode is connected to a previous stage of the reference potential generating unit on the wiring for connecting the reference potential electrode and the reference potential generating unit and an anode is grounded. 
 
     
     
       10. The semiconductor apparatus according to  claim 9 , further comprising:
 another additional protection portion including another additional diode, of which an anode is connected to the cathode of the diode, a cathode is connected to a predetermined power source, having IV (current voltage) characteristics same as the another protection diode. 
 
     
     
       11. The semiconductor apparatus according to  claim 10 , wherein
 a voltage of the predetermined power source is higher than the reference potential. 
 
     
     
       12. The semiconductor apparatus according to  claim 11 , wherein
 the predetermined power source is a power source of the amplifying transistor. 
 
     
     
       13. A potential measuring apparatus comprising:
 a reference potential generating unit and a reference potential electrode configured to supply a reference potential to liquid; 
 a read electrode and an amplifier configured to read a signal from the liquid; and 
 a protection portion configured to protect the amplifier from a negative charge at a previous stage of the amplifier, wherein 
 the reference potential generating unit, the reference potential electrode, the read electrode, the amplifier, and the protection portion are installed on a same substrate.